Various Failures


In my posting on making knife handle-slabs, Commentariat Comrade Gilliel suggested that they would make neat refrigerator magnet buttons.

So, I made a mold. Actually, I made several. The first one, I deemed too small, so I kept making bigger and rounder molds.

Eventually I got to overkill.

A useful technique for making molds that are going to have a point that projects down toward the bottom of the mold, is to pour a foundation layer, then position your object in the foundation before you do the full pour. That way the mold isn’t extremely thin at the bottom.

I built these up, as well. I did a thin layer of blue, then positioned abalone shells on it after it cured. Then I did another layer of blue around the abalone and let that cure, too.

Then, I added a magnet and did a pour that just covered the magnet. Mistake #1: this is a fairly weak magnet. I have magnets that will pull your refrigerator door right off, and I thought I’d use something mild because, well, trying to be nice.

And… FAIL!

The pocked surface of the ball is because of a weird thing I discovered in this experiment: bubbles in silicone normally are bouyant enough to float up to the surface, moving around objects, but the angle of the ball was not oblique enough, so all the bubbles stayed. It’s not that the ball is bubbly: the mold from the first ball is bubbly.

Also, the pigment in the resin is cumulative (naturally, since it’s basically blocking the light) so the thicker your work-piece is, the darker it gets. My natural “bigger is better” algorithm turns out to be badly wrong here.

Meanwhile, the little mold that I filled with the left-over epoxy looks pretty nice! I can make one of those a day and I have about a pound of abalone shell chips left. Anyone want a couple? (specify if I should use deathgrip rare metals magnets or not)

Comments

  1. rq says

    I like the bubbly surface! I wouldn’t mind one, though deathgrip seems a bit much – do you have anything in the middle? (I mean, I need my refrigerator door…)

  2. says

    I’ll bring all the materials home and do a limited production run of these things, and will send them out randomly to those of you whose address I have. (As is my way)

    I think I can find something that’s practical in the magnet arena. Since magnet force falls off with the square of distance, that little bit of resin over the magnet probably makes a big difference.

  3. says

    Pretty!

    Also, the pigment in the resin is cumulative (naturally, since it’s basically blocking the light) so the thicker your work-piece is, the darker it gets. My natural “bigger is better” algorithm turns out to be badly wrong here.

    Personally, I think that the darker version looks nice. Although, I’m biased here. Dark blue is my favorite color, so I’m going to like pretty much anything as long as it has a nice shade of dark blue.

  4. jazzlet says

    I would love one if you are happy to post to the UK and would be happy to give you my address. I like both of them, I tend to be with Leva on the dark blue, but the paler one does show the abalone off better. And strong magnets are better as weak ones get knocked off by the dogs.

    I think understand about the being pretty happy with failure, you learn from each imperfect attempt in a way you don’t if everything goes smoothly. I do not seem to be capable of knitting a pattern ‘as is’ partly because I hate sewing up so will convert a pattern as much as possible to knitting in the round and knitting top down to avoid seams. Also because so very often I like the top bit of one pattern and the bottom of anther so need to meld them or like the shape of one pattern but want it with cables (I love cables) etc.. I have started a particular long vest half a dozen times so far, I will get it right next time! Well I think I will, I’ve worked out how to change the pattern movement to get a V down the center of the back, which should mean that the arm hole edges have a single cable going down them, rather than several cables terminating at them. It has taken several attempts of enough knitting to show where each error was to get to this point, probably more than it would if my thinking wasn’t so fuzzy from the various painkillers, but there isn’t anything that can be done about that with the current state of pain control knowledge. And I’ll have a whole new area to make errors in when I come to the point I’ll start the peplum. Fun in this case as the wool is ok with being unravelled and reknitted, it can be harder if the wool won’t put up with that, I don’t like waste even when I have learnt from the mistakes that caused it.

  5. kestrel says

    @Charly #8: yeah… the problem with most polishing methods is the friction would melt the plastic or resin, so it would have to be done very slowly and would be time consuming.

    However. There is a product called Ice Resin. It is possible that if one coated that one with Ice Resin, it would fill in the voids and give a much better finish.

    I think these are lovely as my favorite color is blue and who doesn’t love sparkly things? My own refrigerator is covered in lots of refrigerator magnets. Perhaps guests think that is crazy, but I consider it to be *their* problem.

  6. kestrel says

    Oh, and @Raucous Indignation, #6: If he _does_ melt or blow himself up, it will have been done very, very meticulously and carefully. ;-)

  7. Dunc says

    It’s not a failure if you either have fun or learn something. Sounds like you did both, therefore it was a great success.

  8. wereatheist says

    magnet force falls off with the square of distance

    As a failed physicist (didn’t complete my degree), I have to disagree.
    The inverse-square law works for monopoles.
    So far, no magnetic monopoles have been found.
    Magnets are dipoles.
    Thus, field strength, and force, go down by distance to the third.

  9. says

    wereatheist@#12:
    Thus, field strength, and force, go down by distance to the third.

    Thank you for the correction.
    Now I am left wondering why it’s to the third!

  10. says

    Wow, thank you all for the overwhelming response!
    I have a crazy busy weekend coming up and will be unable to produce any magnet thingies until after monday (I will explain later) They take a couple days each (but nearly zero effort) to produce, so I’ll start making them and sending them out shortly.

    I think the abalone looks best but I also have the white tooth shells. Feel free to state preferences; I may or may not honor them.

    Hm, unrelated: Pennsylvania where I live is coal country and thus there are no interesting fossils except the fossils of lots and lots and lots of plants. It would be pretty easy for me to find some coal-fossil plants and make magnet resin coal thingies (thereby gifting those in the Commentariat who are Bad with coal!) – that is also something I can easily do if anyone wants.

  11. says

    I think the abalone looks best but I also have the white tooth shells.

    I probably agree about abalone looking better. White tooth shells looked nice too, though.

    It would be pretty easy for me to find some coal-fossil plants and make magnet resin coal thingies

    This sounds like an interesting idea.

  12. says

    If it was fun to do and/or you learned something useful then it is not a failure, to my mind. Disappointing, perhaps, but not fail.
    Also, I’m sure you’re used to seeing *every* single tiniest flaw that no one else seems to see. Or maybe that’s just me. ;)

    I’ve used a coal forge for many years now and I’ve not come across a single coal fossil. I’d be fascinated to see what you come up with.

  13. says

    YOB@#16:
    I’ve used a coal forge for many years now and I’ve not come across a single coal fossil. I’d be fascinated to see what you come up with.

    I’ll make a few and post them. If anyone wants one after that, I’ll do a limited production run.

  14. avalus says

    They are very beautiful!
    Coal fossil thingies sound very interesting!

    (I learned about the play between bubbles and angles the hard way when I was making parts for gaming models. :D)